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14.8 Using Nested Tags

349

tion time. In principle, you could instruct the system to do some validation at

page translation time by using a 

TagExtraInfo

 class. This class has a 

get 

VariableInfo

 method that you can use to check that attributes exist and

where they are used. Once you have defined a subclass of 

TagExtraInfo

,

you associate it with your tag in the tag library descriptor file by means of the

teiclass

 element, which is used just like 

tagclass

. In practice, however,

TagExtraInfo

 is poorly documented and cumbersome to use. 

Listing 14.27 csajsp taglib.tld